Thermostatic wax pot



Aug. 22, 1933. E, RAY

THERMOSTATIC WAX POT Filed April 19. 1929 3 Sheets-Sheet l Aug. 22, 1933. E. J. RAY

THERMOSTATIC WAX POT Filed April 19, 1929 3 Sheets-Sheet 2 Aug. 22, 1933. E. J. RAY 1,923,584

THERMOSTATIC WAX POT Filed April 19. 1929 3Sheets-Sheet 3 'r 100 L I I" i 5;; gm; 31 52 6 9 1 37 We v /v Z6 Wcfness 29 34 zuzerzfor Patented Aug. 22, 1933 t Z r UNITE stares ears Eugene J. Ray, Beverly, Mass.,assignor to United Shoe Machinery Corporation, Paterson,.N. J., a Corporation of New Jersey Application April 19, 1929. Serial No. 356,475

7 Claims. (Cl. 21944) .The present invention has relation to wax to be used. Upon the bracket is pivotally sup-. thread sewing machines such as are employed ported by means of a stud 2 a cover 4 having a in the manufacture of shoes, and to the wax flaring lower portion 5 which overhangs and pots which are used in connection with such closes the open upper end of the wax receptacle 5 machines for the purpose of impregnating the 1. The latter is supported as is usual in this 60.

thread with wax or similar substance previous, class of deviceswith its lip inpro-ximity to the to the incorporation of the thread in the seam flaring portion 5 when in working relation and formed by the sewing machine. with capacity for movement downwardly away The invention has particular relation to the from the bracket 3 to give access-to the parts means employed in connection with such wax enclosed within. p 65 pots for heating the wax or other similar mate- The means for heating the wax-placed within rial for the purpose. of rendering it fluid and the receptacle 1 comprises a pair of electric capable of thoroughly permeating the thread heating elements 6, '7, which are of elongated as the latter passes through it on its way from cylindrical shape, disposed within their respecthe supply to the thread handling devices or" tive chambers 8 and 9, formed within a housing 70 the sewing machine. 10 of heat-conducting metal which depends The object of the present invention isto profrom the lower surface of the bracket 3, being vide. a novel and improved Wax pot including attached thereto by meansof screws 11. and with heating means for the wax or other similar suban asbestos gasket interposed to reduce the pass stance, said heating means having advantages. sage of heat from the housing. Thehousing is 7 over prior constructions in simplicity, cheap-. provided with wings l3, 14 extending laterally ness, and compactness; in affording improved, therefrom inparallel relation and perforated to thermostatic control means'for regulating autopermit iree circulation of the molten wax, and matically the electric heating units employed joined at their'bottom extremities by a web 15 therein so that the wax shall always be kept at upon which web betweenthe said wings a porcethe proper temperature, and in provision for lain thread guide-17 is secured by a yoke 16. quick and easy removal of the heating units and Through this guide the thread passes as it is the thermostatic controlmeans in the event of drawnfrc-m the supply. This guide insures the injury thereto or need for adjustment thereof, thread being passed down below the level of the 30 without removal or disturbance of the parts melted wax as it is drawn through the wax pot. a

other than those needing attention. In its upward'travel, the thread is passed, after With this object in .view, the invention 0011- leaving the porcelain guide 17, through the slot sists in the novel and improved features, con in an auxiliary stripper 18 attached by screw 19 structions, and combination of parts hereinafter to the wing 13-to remove the major portion of described and particularly pointed out in the v the excess wax, and thence is caused to pass be 0 claims. tween an eccentrically grooved' stud 20 and a .An illustrative embodiment of the preferred presser spring 21 bearing against said stud and form of the invention is shown in the accommounted by means of a screw 22 upon the upper panying drawings in which Fig. 1 is a side eleend of the housing 10, the spring acting as'a 40 vation, partly in section and partly broken away, wiper to complete the removal of excess wax 95 of a wax pot including thenovel heating means; adhering to the thread. The stud 20 extends Fig. 2 is a front elevation of certain of the horizontally from the end of an arm 23 formed parts shown in Fig. 1, the wax receptacle being integrally upon the upper end of the housing 10, shown in section and certain of the other parts and thus shares the heat generated in the hous broken away; Fig. 3 is a plan view with the ing Thence the thread travels to the thread cover plate over "the junction-block removed to handling instrumentalities of the machine. The disclose details of the connections as made wings 13 and 14 upon each side of the path of. through the use of said junction-block; Fig 4 the thread efiectively prevent lumps of the cold is a-detail in vertical section showing the therwax which may be dropped into the wax recep-: V

mostatic circuit breaker in closedrelation with tacle to replenish the supply, from coming into 1 respect to its contact points. i 7 contact with the thread.

The wax receptacle 1 is supported from a The chambers 8 and 9 are formed as longibracket 3 which is adapted to be secured to the tudinal passages extending through the housing frame or column of the sewing machine in confrom end to end thereof, so that the cylindrical nection with which the thread waxing device is heating units 6 and 7 may be easily removed 10 from their respective chambers in the event of their swelling and binding therein, by the use of a tool employed to push them upward and introduced through the bottom of the housing 5 while the wax receptacle 1 is lowered. Each chamber is threaded at its lower extremity and fitted with a plug 25, 26 equippedwith a gasket, and serving to close the lower end. 01' the chamber and exclude melted wax therefrom.

The housing includes within it a vertical passage 27 extending at its lower end into a chamber 28 lying below the level at which the wax is designed to be maintained and which has a portion 29 of circular area disposed in close proximity to the chambers 8 and 9. holding the heating units, being separated therefrom by the thin wall 100. In this portion 29 of the chamber is located the thermostatic controlling means or circuit breaker for governing automatically the 0 flow of electric current employed to energize one of the two heating units.

sponsive element 30 ofthe well k nown' concavoconvex type having when relatively cool a concavity facing in one direction and adapted upon rise of its temperature to assume an opposite curvature or bulge, the transition in curvature taking place suddenly upon the attainment of a predetermined degree of temperature. This heat responsive element is mounted upon a stud31 passing through its center, being secured thereon by a nut 32, and is located in close proximity to the wall 100, which in turn is close to the surfaces of the heating units 6 and 7, to the full "heat from which itis exposed, With the interposition only of the thin wall 100' of the heatconducting material of the housing, and with the least possible air-space separating it from the surface of such wall. The bi-metallic heat res- 49 =ponsive member 30 is provided at three equidistant points about its edge-portion with discs 80 of current-conducting metal, insulated from the metal of the member 30, and adapted when the member is cool to make contact with, and

bridge the gaps in, an interrupted segmental ring 81 affixed in insulated relation upon a circular plate 34 secured within a recess formed at the mouth of the portion 29 of the chamber 28."

r The plate 34 is heldin place by'means of screws "35 threaded into the material of the housing with their heads overlapping marginal portions of the circular plate. The chamber 28 is accessible from the outside of the housing through r a large opening permitting the installation and removel of the thermostatic circuit-breaker therethrough, without disturbing the connection between the bracket 3 and the housing 10, such opening being closed by a large plug 36 which said opening to keep was: from entering the housing and interfering with the action of the parts therein.

The leads carrying electric current to the .heating units and. the thermostatic circuit break- "er, as well as the leads bringing such current from its source, are brought to a common junction-block located in an easily accessible position upon the bracket 3 and arranged to permit easy and rapid disconnection of any one or more '"of the three elements included in the housing without disturbing the electrical connections to the remaining ones.

.ment' of any one of the said three elements.

Such thermostatic control means comprise a bi-metallic heat re-- .is equipped with a gasket 37 and threaded into This feature is of importancethrough expediting the repair or replace.

like compartment 39, or junction-box, as it may be termed, integrally formed in connection with the bracket 3, a junction-block 40 of insulating material, secured in place by a screw 41 passed through it and threaded into the bottom of said compartment 39, and having two deep grooves 42 extending across its width and a third groove 43 disposed between said grooves and extending partway across its Width. The leads 44 bringing electric current to energize the heating units from a suitablesource are equippedwith binding lugs which are engaged and held within the respective grooves 42 by means of binding posts or screws 45, 46. received in threaded holes in the insulatingjunction-block 40. The leads 47, 48 carrying the energizing current to the heat- .ing unit '7 which is of low heat-producing 'capacity are joined respectively to the ends of the leads 44 by means of the said two binding posts or screws 45, 46, said leads being brought up through the chamber 9 in the housing and through an opening 49 coinciding therewith formed in the bottom of the compartment 39.

With this arrangement the low power heating unit is'in circuit and continuously acting so long as the current is permitted to flow from the source through the line leads 44.

The leads 50 and 51 from the heatingelement 6, which has the greater heat producing capacity,

are brought up throughthe upper portion of the chamber 8 and through an opening 52' coinciding therewith in the bottom of the compartQ 54 leadingto one of a pair of binding posts 33 in connection with the interrupted ring 81 which is engaged by the discs 80 upon the heat" responsive element 30. The lead 55 which extends upward from the other binding post 33 is combined with binding post or screw 46 and thus is connected with the source of electric suitable opening 56 in the bottom of the com-. partment 39 communicates with the passage 27 through which the conductors 54 and 55 are,

power flowing through the conductors 4'4.

brought up to the junction-block 40. With this arrangement of the'parts, the lowpower heating unit '7 is always in circuit with the line leads 44 and receives energizing current therefrom so long as the current is allowed The high-powerheating unit 6 isconnected in series to flow through leads 44 from its source.

with the thermostatic control means, or circuitbreaker, and these two combined elements'are connected in parallel with the low-power heating unit 7 across the line leads 44, so that current may passsimultaneously through the two heating units to melt the wax placed in the receptacle 1 around the central housing 10L When the heat produced by the combined efiect of the two units has raised the temperature or" the heat-responsive member 30 to the predetermined" degree, the member 30 assumes its reverse curvature with a snap. Up to this moment, the discs 80 have bridged the gaps in the interrupted ring 81 and formed portions of the circuit followed by the current in passing through the high i power heating unit 6, and have served to help carry the current from one of the binding'posts 33 to the other thereof. Thus, the heat-rd.

loo"

sponsive member 30, in reversing its curvature, static circuit breaker included within said 1101151 has removed the discs'BO bodily from the circuit and interrupted the flow of current to heating unit 6. Thereafter the low-power. unit 7 alone continuesto supply heat, until the heat-responsive member has fallen a predetermined number of degrees in temperature, when it reverses its curvature and snaps back bringing discs to again into contact with the ring 81, and re-establishing the flow of energizing current through the high-power heating unit 6.

It has been found that the location of the concavo--convex type of heat-responsive member in close proximity to the heating units and exposed to the maximum heat given off therefrom while all the elements are included in a housing so that said member may follow closely the temperature changes of the heating units gives results which are superior, in the way of keeping the wax properly melted and of avoidance of burning the wax, to those results secured through separating such member from the heating units by insulating air-spaces, or by immersing it in the wax itself. This is because of the characteristics of this type of thermostatic member, which require the building-up of considerable stresses within the bi-metallic thickness before reversal of curvature can occur Hence the circuit-opening temperature is a considerable number of degrees of heat above the circuit-closing temperature, and this change of temperature between maximum and minimum has no objectionable effect on the wax when the heating units and the thermostat are arrange as described within the housing 10, because through its spaced relation, the temperature of the wax is allowed to lag behind the high limit and remain above the low limit of the temperature variation of the metal or" the thermostat. Thus by means of the unique combination and arrangement of the parts in the invention, the advantages of the concavo-convex type of thermostat with its quick, wide, and energetic mcvement in breaking the circuit, which eliminates trembling and arcing and greatly prolongs the life of its contact-points, are secured in a thread-waxing device while avoiding the apparent drawbacks arising from its delayed action.

When it is desired to remove any one of the heating elements contained within the housing 10 for replacement or repair, the wax-receptacle 1 is lowered to give access to the housing 10,

the appropriate plug 25, 26, 36 is removed, and a cover 60, secured to the rim of the junctionbox 39 by means of screws 61 received in. screwholes 62 at its corners, is likewise removed to give access to the junction-block 40. Any one of the three elements combined within the housing 10 may be speedily disconnected from the binding posts 45, 46, 53, without disturbing the remaining elements, and may be then removed from the housing, the heating elements by being lifted up through the junction-box and the thermostat by being withdrawn through the opening closed by plug 36. The element is qfickly replaced by a reversal of the procedure detailed.

Having thus described the invention what is claimed is:

1. A wax pot for wax thread sewing machines having, in combination, a receptacle for the wax, means for guiding the thread throughthe receptacle, an electrical heating unit within the receptacle, a housing to exclude the wax'from contact with said heating unit, andv a thermoing and in close proximity to said heating unit to receive heatdirectly from the latter and con-Q trol the electric current energizing the heating; unit.

2. A wax pot for thread sewing machines having, in combination, a receptacle for the wax, means for guiding the thread through the receptacle, an electrical heating unit within the receptacle, a housing to exclude the wax from contact with said heating unit, a lateral aperture in said housing, a removable plug closing aperture against admission of wax, and a thermostatic circuit breaker adapted to be received within said aperture into close proximity with the heating unit, and controlling the electric current energizing the latter. i

3. Heating means for the wax pot of a wax thread sewing machine having, in combination, a housing, an insulated junction-block combined therewith and adapted to be connected with a source of electric current, an electric heating unit within said housing and having its terminals combined with said junction block, .and a thermostat connected in series with said heating unit and having its terminals also combined with said junction block so that disconnection and removal of the heating unit may be effected without disturbing said thermostat.

4. Heating means for the wax pot of a wax thread sewing machine having, in combination,

a housing, an insulated junction-block combined therewith. having a plurality of binding posts of which two are adapted to be connected to a source of electric current, and a third independent therefrom, an electric heating unit removably positioned within said housing having its terminals respectively combined with one of the said two binding posts and with the third independent binding post, and a thermostat having its other of said two binding posts and with the third independent binding post, whereby the heating unit may be disconnected and removed without disturbingthe thermostat and its connections.

5. A wax pot for wax thread sewing machines having, in combination, a receptacle for the wax, means for guiding the, thread through the receptacle, an electrical heating unit within the receptacle, a housing to exclude the wax from contact with said heating unit, and a 'concavoconvex thermostatic circuit-breaker mounted in the housing in proximity to the heating unit to receive heat directly from the latter and control the electric current energizing the heating unit and arranged to follow closely in its temperature the rise of temperature of the heating element, and disposed in spaced relation with respect to the wax, to permit a relative divergence in temperature between. the thermostat and the wax.

6. A wax pot for wax thread sewing machines having, in combination, a receptacle for the wax, means for guiding the thread through the receptacle, a housing extending into the wax in the receptacle, an electrical heatingunit within the housing, and a concavo-convex thermostatic circuit-breaker in circuit with the electrieal heating unit mounted in the housing. in proximity to theheating unit to receive heat directly from the latter and control the electrio current energizing the heating unit and separated from the wax by the housing, the arrangement of said circuit breaker, heating terminals respectively combined with the tricalheating unit within the receptacle, a housing to exclude the wax from contact with said heating unit; and an independently remov able thermostatic circuit breaker included within said housing and in close proximity to said heating unit to receive heat directly from the latter and control the electric current energizing the heating unit.

EUGENE J. RAY. 

